1. Field of the Invention
This specification relates to a drain pump for a laundry treating apparatus capable of draining or circulating washing water introduced from a drum.
2. Background of the Invention
A laundry treating apparatus serves to remove contaminations on laundry by introducing clothes, bedclothes, etc. (hereinafter, will be referred to as laundry) into a drum, and performs a washing process, a rinsing process, a dehydrating process, a drying process, etc.
The laundry treating apparatus is classified into a top loading type and a front loading type according to a method to introduce laundry into a drum. Generally, such a front loading type of washing machine is called a drum washing machine.
FIG. 1 shows an appearance of a drum washing machine, and FIG. 2 shows an inner shape of the drum washing machine of FIG. 1.
The laundry treating apparatus includes a cabinet 11 which forms an appearance thereof, a drum 21 rotatably mounted in the cabinet 11 and into which laundry is introduced, a lifter (not shown) installed in the drum 21, and a door 12 installed on a front surface of the cabinet 11. A detergent introducing opening cover 13 for covering a detergent introducing opening is disposed at a lower part of the cabinet 11. The laundry treating apparatus further includes a duct 15 and a heat exchanger 20, because air should circulate in order to dry laundry accommodated in the drum 21.
The front loading type of washing machine, i.e., the drum washing machine 10, performs a washing process by rotating the drum 21 when laundry is accommodated in the drum and water is supplied to the drum, and performs a rinsing process, a dehydrating process, etc. to discharge washing water to the outside by a drain pump. The drum washing machine 10 is provided with a circulation pump for circulating water inside the drum 21 during a washing process, and a drain pump for discharging washing water generated during the washing process to the outside.
In the conventional drum washing machine, the circulation pump for circulating washing water and the drain pump for discharging washing water are driven by separate motors. In this case, an installation space is restricted, and high costs are required because a plurality of motors are installed.
In order to solve such problems, one motor and one impeller are used, and a circulation pump and a drain pump are implemented by converting a rotation direction of the impeller. However, in case of performing a drain process and a circulation process by converting a direction of a flow path of washing water, the washing water may backflow toward an undesired flow path during the circulation process or the drain process.
Accordingly, required is an apparatus which does not restrict an installation space inside a laundry treating apparatus by serving as a drain pump and a circulation pump by using a single motor and a single impeller, the apparatus capable of preventing washing water from backflowing to an undesired flow path during a drain process or a circulation process.